In the past, power modules for hybrid or electric automobiles have often provided cooling on a single side of an electronic device, such as a power MOSFET (metal oxide semiconductor field effect transistor), IGBT (insulated gate bipolar transistor), or other component. Due to the placement of such power modules on heat sinks, lead frame terminals of such devices may come in close proximity to the heat sinks. Further, past power modules typically have used wire bonds to one or more sides of the power module device. The use of wire bonds creates problems with high assembly time and capital equipment costs, as well as high parasitic inductances that cause voltage overshoots. Still further, wire bonds can lead to failures due to repetitive power cycling.
However, in practice, it can be difficult to achieve double-sided cooling due to mechanical tolerances of the various components making up the power module. Such modules with double-sided cooling may include two DBC (direct bond copper) substrates, each made up of two copper layers and a ceramic layer, and each with a thickness tolerance, two solder layers and a power semiconductor device sandwiched between the two DBC substrate layers. Required tolerances on power module thicknesses can make it difficult to provide heat sinking, especially if trying to heat sink two adjacent devices, each with their own thickness and flatness tolerances.